how to randomly vary 2 numbers?

Hi! I want to generate a column of 30 randomly varying -1s and 1s. How can I do that? I was trying randi([-1:2:1],30,1) but that gives me zeros too and I don't want zeros, only -1 and 1. Thanks

Answer 1

[John Petersen]

x = 2*round(rand(30,1)) - 1;

[Isabel]

This gives me a column of zeros only. Thanks anyways

[John Petersen]

No it doesn't. Maybe you didn't grab the whole line?

[Isabel]

Sorry, it does work, my bad. I think I din't copy the whole formula or something. Thank you very much for your answer!

Answer 2

[Andrei Bobrov]

eg

A = (rand(5) > .5) + 0;
A(~A) = -1;

or

A = 2*randi([0 1],30,1) - 1;

[Isabel]

Thanks! this works well

Answer 3

[Orazio Sorgonà]

I use

A = -1^(randi([1,2]));